Database Systems: Design, Implementation, and Management, 10th Edition – Flashcards
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ad hoc query
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A "spur-of-the-moment" question.
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analytical database
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A database focused primarily on storing historical data and business metrics used exclusively for tactical or strategic decision making.
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business intelligence
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A comprehensive, cohesive, and integrated set of tools and processes used to capture, collect, integrate, store, and analyze data with the purpose of generating and presenting information to support business decision making.
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centralized database
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A database located at a single site.
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data
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Raw facts, or facts that have not yet been processed to reveal their meaning to the end user.
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data anomaly
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A data abnormality in which inconsistent changes have been made to a database. For example, an employee moves, but the address change is not corrected in all files in the database.
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data dependence
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A data condition in which data representation and manipulation are dependent on the physical data storage characteristics.
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data dictionary
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A DBMS component that stores metadata—data about data. Thus, the data dictionary contains the data definition as well as their characteristics and relationships. A data dictionary may also include data that are external to the DBMS. Also known as an information resource dictionary.
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data inconsistency
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A condition in which different versions of the same data yield different (inconsistent) results.
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data independence
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A condition in which data access is unaffected by changes in the physical data storage characteristics.
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data integrity
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In a relational database, a condition in which the data in the database comply with all entity and referential integrity constraints.
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data management
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A process that focuses on data collection, storage, and retrieval. Common data management functions include addition, deletion, modification, and listing.
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data processing (DP) manager
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A DP specialist who evolved into a department supervisor. Roles include managing technical and human resources, supervising senior programmers, and troubleshooting the program. Also known as a data manager (DM).
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data quality
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A comprehensive approach to ensuring the accuracy, validity, and timeliness of data.
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data redundancy
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A condition in which a data environment contains redundant (unnecessarily duplicated) data.
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data warehouse
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An integrated, subject-oriented, time-variant, nonvolatile collection of data that provides support for decision making, according to Bill Inmon, the acknowledged "father of the data warehouse."
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database design
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The process that yields the description of the database structure and determines the database components. Database design is the second phase of the Database Life Cycle.
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database management system (DBMS)
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The collection of programs that manages the database structure and controls access to the data stored in the database.
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database system
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An organization of components that defines and regulates the collection, storage, management, and use of data in a database environment.
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desktop database
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A single-user database that runs on a personal computer.
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discipline-specific database
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A database that contains data focused on specific subject areas.
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distributed database
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A logically related database that is stored in two or more physically independent sites.
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enterprise database
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The overall company data representation, which provides support for present and expected future needs.
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Extensible Markup Language (XML)
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A metalanguage used to represent and manipulate data elements. Unlike other markup languages, XML permits the manipulation of a document's data elements. XML facilitates the exchange of structured documents such as orders and invoices over the Internet.
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field
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An alphabetic or numeric character or group of characters that defines a characteristic of a person, place, or thing. For example, a person's Social Security number, address, phone number, and bank balance all constitute fields.
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file
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A named collection of related records.
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information
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The result of processing raw data to reveal its meaning. Information consists of transformed data and facilitates decision making.
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islands of information
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In the old file system environment, pools of independent, often duplicated, and inconsistent data created and managed by different departments.
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knowledge
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The body of information and facts about a specific subject. Knowledge implies familiarity, awareness, and understanding of information as it applies to an environment. A key characteristic is that new knowledge can be derived from old knowledge.
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logical data format
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The way a person views data.
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metadata
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Data about data; that is, data about data characteristics and relationships. See also data dictionary.
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NoSQL
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A new generation of database management systems that is not based on the traditional relational database model.
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online analytical processing (OLAP)
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Decision support system (DSS) tools that use multidimensional data analysis techniques. OLAP creates an advanced data analysis environment that supports decision making, business modeling, and operations research.
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online transaction processing (OLTP)
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The systems that support a company's day-to-day operations. Databases that support OLTP are known as OLTP databases, transactional databases, or operational databases.
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operational database
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A database designed primarily to support a company's day-to-day operations. Also known as a transactional database or production database.
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performance tuning
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Activities that make a database perform more efficiently in terms of storage and access speed.
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physical data format
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The way a computer "sees" (stores) data.
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query
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A question or task asked by an end user of a database in the form of SQL code. A specific request for data manipulation issued by the end user or the application to the DBMS.
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query language
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A nonprocedural language that is used by a DBMS to manipulate its data. An example of a query language is SQL.
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query result set
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The collection of data rows returned by a query.
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record
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A collection of related (logically connected) fields.
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semistructured data
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Data that have already been processed to some extent.
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single-user database
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A database that supports only one user at a time.
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structural dependence
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A data characteristic in which a change in the database schema affects data access, thus requiring changes in all access programs.
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structural independence
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A data characteristic in which changes in the database schema do not affect data access.
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structured data
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Unstructured data that have been formatted to facilitate storage, use, and information generation.
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Structured Query Language (SQL)
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A powerful and flexible relational database language composed of commands that enable users to create database and table structures, perform various types of data manipulation and data administration, and query the database to extract useful information.
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transactional database
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A database designed to keep track of the day-to-day transactions of an organization.
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unstructured data
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Data that exist in their original, raw state; that is, in the format in which they were collected.
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XML
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See Extensible Markup Language (XML).
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XML database
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A database system that stores and manages semistructured XML data.
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American National Standards Institute (ANSI)
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The group that accepted the DBTG recommendations and augmented database standards in 1975 through its SPARC committee.
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attribute
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A characteristic of an entity or object. An attribute has a name and a data type.
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Big Data
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A movement to find new and better ways to manage large amounts of Web-generated data and derive business insight from it, while simultaneously providing high performance and scalability at a reasonable cost.
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business rule
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A description of a policy, procedure, or principle within an organization. For example, a pilot cannot be on duty for more than 10 hours during a 24-hour period, or a professor may teach up to four classes during a semester.
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Chen notation
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See entity relationship (ER) model.
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class
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A collection of similar objects with shared structure (attributes) and behavior (methods). A class encapsulates an object's data representation and a method's implementation. Classes are organized in a class hierarchy.
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class diagram
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A diagram used to represent data and their relationships in UML object notation.
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class diagram notation
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The set of symbols used in the creation of class diagrams.
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class hierarchy
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The organization of classes in a hierarchical tree in which each parent class is a superclass and each child class is a subclass. See also inheritance.
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conceptual model
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The output of the conceptual design process. The conceptual model provides a global view of an entire database and describes the main data objects, avoiding details.
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conceptual schema
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A representation of the conceptual model, usually expressed graphically. See also conceptual model.
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connectivity
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The classification of the relationship between entities. Classifications include 1:1, 1:M, and M:N.
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constraint
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A restriction placed on data, usually expressed in the form of rules. For example, "A student's GPA must be between 0.00 and 4.00." Constraints are important because they help to ensure data integrity.
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Crow's Foot notation
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A representation of the entity relationship diagram that uses a three-pronged symbol to represent the "many" sides of the relationship.
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data definition language (DDL)
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The language that allows a database administrator to define the database structure, schema, and subschema.
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data manipulation language (DML)
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The set of commands that allows an end user to manipulate the data in the database. The commands include SELECT, INSERT, UPDATE, DELETE, COMMIT, and ROLLBACK.
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data model
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A representation, usually graphic, of a complex "real-world" data structure. Data models are used in the database design phase of the Database Life Cycle.
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entity
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A person, place, thing, concept, or event for which data can be stored. See also attribute.
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entity instance
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In ER modeling, a specific table row. Also known as an entity occurrence.
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entity occurrence
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See entity instance.
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entity relationship (ER) model (ERM)
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A data model that describes relationships (1:1, 1:M, and M:N) among entities at the conceptual level with the help of ER diagrams. The model was developed by P. Chen in 1975.
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entity relationship diagram (ERD)
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A diagram that depicts an entity relationship model's entities, attributes, and relations.
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entity set
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In a relational model, a grouping of related entities.
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eventual consistency
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A model for database consistency in which updates to the database will propagate through the system so that all data copies will be consistent eventually.
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extended relational data model (ERDM)
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A model that includes the object-oriented model's best features in an inherently simpler relational database structural environment.
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Extensible Markup Language (XML)
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A metalanguage used to represent and manipulate data elements. Unlike other markup languages, XML permits the manipulation of a document's data elements. XML facilitates the exchange of structured documents such as orders and invoices over the Internet.
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external model
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The application programmer's view of the data environment. Given its business focus, an external model works with a data subset of the global database schema.
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external schema
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The specific representation of an external view; the end user's view of the data environment.
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hardware independence
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A condition in which a model does not depend on the hardware used in the model's implementation. Therefore, changes in the hardware will have no effect on the database design at the conceptual level.
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hierarchical model
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An early database model whose basic concepts and characteristics formed the basis for subsequent database development. This model is based on an upside-down tree structure in which each record is called a segment. The top record is the root segment. Each segment has a 1:M relationship to the segment directly below it.
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inheritance
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In the object-oriented data model, the ability of an object to inherit the data structure and methods of the classes above it in the class hierarchy. See also class hierarchy.
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internal model
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In database modeling, a level of data abstraction that adapts the conceptual model to a specific DBMS model for implementation. The internal model is the representation of a database as "seen" by the DBMS. In other words, the internal model requires a designer to match the conceptual model's characteristics and constraints to those of the selected implementation model.
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internal schema
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A representation of an internal model using the database constructs supported by the chosen database.
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key-value
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A data model based on a structure composed of two data elements: a key and a value, in which every key has a corresponding value or set of values. The key-value data model is also called the associative or attribute-value data model.
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logical design
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A stage in the design phase that matches the conceptual design to the requirements of the selected DBMS and is therefore software-dependent. Logical design is used to translate the conceptual design into the internal model for a selected database management system, such as DB2, SQL Server, Oracle, IMS, Informix, Access, or Ingress.
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logical independence
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A condition in which the internal model can be changed without affecting the conceptual model. (The internal model is hardware-independent because it is unaffected by the computer on which the software is installed. Therefore, a change in storage devices or operating systems will not affect the internal model.)
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many-to-many (M:N or *..*) relationship
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Associations among two or more entities in which one occurrence of an entity is associated with many occurrences of a related entity and one occurrence of the related entity is associated with many occurrences of the first entity.
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method
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In the object-oriented data model, a named set of instructions to perform an action. Methods represent real-world actions, and are invoked through messages.
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network model
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A data model standard created in the late 1960s that represented data as a collection of record types and relationships as predefined sets with an owner record type and a member record type in a 1:M relationship.
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NoSQL
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A new generation of database management systems that is not based on the traditional relational database model.
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object
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An abstract representation of a real-world entity that has a unique identity, embedded properties, and the ability to interact with other objects and itself.
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object-oriented data model (OODM)
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A data model whose basic modeling structure is an object.
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object-oriented database management system (OODBMS)
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Data management software used to manage data in an object-oriented database model.
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object/relational database management system (O/R DBMS)
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A DBMS based on the extended relational model (ERDM). The ERDM, championed by many relational database researchers, constitutes the relational model's response to the OODM. This model includes many of the object-oriented model's best features within an inherently simpler relational database structure.
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one-to-many (1:M or 1..*) relationship
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Associations among two or more entities that are used by data models. In a 1:M relationship, one entity instance is associated with many instances of the related entity.
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one-to-one (1:1 or 1..1) relationship
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Associations among two or more entities that are used by data models. In a 1:1 relationship, one entity instance is associated with only one instance of the related entity.
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physical independence
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A condition in which the physical model can be changed without affecting the internal model.
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physical model
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A model in which physical characteristics such as location, path, and format are described for the data. The physical model is both hardware- and software-dependent.
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relation
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In a relational database model, an entity set. Relations are implemented as tables. Relations are related to each other through the sharing of a common entity characteristic (a value in a column).
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relational database management system (RDBMS)
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A collection of programs that manages a relational database. The RDBMS software translates a user's logical requests (queries) into commands that physically locate and retrieve the requested data. A good RDBMS also creates and maintains a data dictionary to help provide data security, data integrity, concurrent and easy access, and system administration to the data through a query language (SQL) and application programs.
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relational diagram
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A graphical representation of a relational database's entities, the attributes within those entities, and the relationships among the entities.
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relational model
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Developed by E. F. Codd of IBM in 1970, it represented a major breakthrough for users and designers because of its conceptual simplicity. The relational model is based on mathematical set theory and represents data as independent relations. Each relation (table) is conceptually represented as a matrix of intersecting rows and columns. The relations are related to each other through the sharing of common entity characteristics (values in columns).
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relationship
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An association between entities.
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schema
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A logical grouping of database objects, such as tables, indexes, views, and queries, that are related to each other. Usually, a schema belongs to a single user or application.
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segment
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In the hierarchical data model, the equivalent of a file system's record type.
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semantic data model
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The first of a series of data models that more closely represented the real world, modeling both data and their relationships in a single structure known as an object. The SDM, published in 1981, was developed by M. Hammer and D. McLeod.
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software independence
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A property of any model or application that does not depend on the software used to implement it.
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sparse data
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A case in which the number of table attributes is very large but the number of actual data instances is low.
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subschema
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In the network model, the portion of the database "seen" by the application programs that produce the desired information from the data in the database.
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table
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A matrix composed of intersecting rows (entities) and columns (attributes) that represents an entity set in the relational model. Also called a relation.
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tuple
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In the relational model, a table row.
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Unified Modeling Language (UML)
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A language based on object-oriented concepts that provides tools such as diagrams and symbols to graphically model a system.
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associative entity
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See composite entity.
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attribute domain
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See domain.
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bridge entity
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See composite entity.
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candidate key
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A minimal superkey; that is, a key that does not contain a subset of attributes that is itself a superkey. See key.
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closure
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A property of relational operators that permits the use of relational algebra operators on existing tables (relations) to produce new relations.
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composite entity
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An entity designed to transform an M:N relationship into two 1:M relationships. The composite entity's primary key comprises at least the primary keys of the entities that it connects. Also known as a bridge entity. See also linking table.
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composite key
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A multiple-attribute key.
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data dictionary
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A DBMS component that stores metadata—data about data. Thus, the data dictionary contains the data definition as well as their characteristics and relationships. A data dictionary may also include data that are external to the DBMS. Also known as an information resource dictionary.
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dependent
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An attribute whose value is determined by another attribute.
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determinant
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Any attribute in a specific row whose value directly determines other values in that row.
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determination
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The role of a key. In the context of a database table, the statement "A determines B" indicates that knowing the value of attribute A means that the value of attribute B can be looked up.
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domain
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In data modeling, the construct used to organize and describe an attribute's set of possible values.
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entity integrity
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The property of a relational table that guarantees each entity has a unique value in a primary key and that the key has no null values.
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equijoin
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A join operator that links tables based on an equality condition that compares specified columns of the tables.
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flags
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Special codes implemented by designers to trigger a required response, alert end users to specified conditions, or encode values. Flags may be used to prevent nulls by bringing attention to the absence of a value in a table.
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foreign key (FK)
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An attribute or attributes in one table whose values must match the primary key in another table or whose values must be null. See key.
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full functional dependence
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A condition in which an attribute is functionally dependent on a composite key but not on any subset of the key.
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functional dependence
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Within a relation R, an attribute B is functionally dependent on an attribute A if and only if a given value of attribute A determines exactly one value of attribute B. The relationship "B is dependent on A" is equivalent to "A determines B," and is written as AB.
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homonym
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The use of the same name to label different attributes. Homonyms generally should be avoided. Some relational software automatically checks for homonyms and either alerts the user to their existence or automatically makes the appropriate adjustments. See also synonym.
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index
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An ordered array of index key values and row ID values (pointers). Indexes are generally used to speed up and facilitate data retrieval. Also known as an index key.
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index key
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See index.
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inner join
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A join operation in which only rows that meet a given criterion are selected. The join criterion can be an equality condition (natural join or equijoin) or an inequality condition (theta join). The inner join is the most commonly used type of join. Contrast with outer join.
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join column(s)
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Columns that join two tables. The join columns generally share similar values.
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key
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An entity identifier based on the concept of functional dependence; keys may be classified in several ways. See also superkey, candidate key, primary key (PK), secondary key, and foreign key.
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key attribute
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The attributes that form a primary key.
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left outer join
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In a pair of tables to be joined, a join that yields all the rows in the left table, including those that have no matching values in the other table. For example, a left outer join of CUSTOMER with AGENT will yield all of the CUSTOMER rows, including the ones that do not have a matching AGENT row. See also outer join and right outer join.
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linking table
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In the relational model, a table that implements an M:M relationship. See also composite entity.
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natural join
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A relational operation that links tables by selecting only the rows with common values in their common attribute(s).
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null
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In SQL, the absence of an attribute value. Note that a null is not a blank.
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outer join
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A relational algebra JOIN operation that produces a table in which all unmatched pairs are retained; unmatched values in the related table are left null. Contrast with inner join. See also left outer join and right outer join.
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predicate logic
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Used extensively in mathematics to provide a framework in which an assertion (statement of fact) can be verified as either true or false.
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primary key (PK)
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In the relational model, an identifier composed of one or more attributes that uniquely identifies a row. Also, a candidate key selected as a unique entity identifier. See also key.
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referential integrity
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A condition by which a dependent table's foreign key must have either a null entry or a matching entry in the related table. Even though an attribute may not have a corresponding attribute, it is impossible to have an invalid entry.
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relational algebra
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A set of mathematical principles that form the basis for manipulating relational table contents; the eight main functions are SELECT, PROJECT, JOIN, INTERSECT, UNION, DIFFERENCE, PRODUCT, and DIVIDE.
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right outer join
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In a pair of tables to be joined, a join that yields all of the rows in the right table, including the ones with no matching values in the other table. For example, a right outer join of CUSTOMER with AGENT will yield all of the AGENT rows, including the ones that do not have a matching CUSTOMER row. See also left outer join and outer join.
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secondary key
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A key used strictly for data retrieval purposes. For example, customers are not likely to know their customer number (primary key), but the combination of last name, first name, middle initial, and telephone number will probably match the appropriate table row. See also key.
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set theory
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A part of mathematical science that deals with sets, or groups of things, and is used as the basis for data manipulation in the relational model.
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superkey
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An attribute or attributes that uniquely identify each entity in a table. See key.
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synonym
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The use of different names to identify the same object, such as an entity, an attribute, or a relationship; synonyms should generally be avoided. See also homonym.
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system catalog
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A detailed system data dictionary that describes all objects in a database.
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theta join
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A join operator that links tables using an inequality comparison operator (, =) in the join condition.
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tuple
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In the relational model, a table row.
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union-compatible
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Two or more tables that share the same column names and have columns with compatible data types or domains.
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unique index
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An index in which the index key can have only one associated pointer value (row).
